Lions can be separated into three age classes based on weight, pelage characteristics, tooth eruption and
wear, and tissue changes that indicate breeding by females.
Estimating Mountain Lion Age Classes
Reliability: #1 teeth, #2 bars, #3 spots
Kitten (5-6 months)
At 4 months deciduous canines are fully erupted (10mm). Permanent canines begin to erupt at 6-8 months
and are fully erupted at 15-16 months. Penis sheath is dark. Spots are present on hind leg, bar on foreleg. Faint spots are
visible elsewhere on upper body.
Subadult (1 1/2 -2 1/2 years)
Canine teeth are fully erupted (males-26mm, females-22-25mm). Teeth are white and sharp, no canine
ridge is present. Bars are present on forelegs, spots inside hind legs, penis sheath is dark.
Young Adult (2 1/2- 4 years)
Teeth are slightly stained, very little wear is evident, canine ridge appears just below gums. Spots
are present inside hind legs and bars on forelegs. Vulva spot on females is dark.
Mature Adult (4+ years)
Teeth are well stained, canine wear is evident, outer incisors are worn almost even with other incisors.
Canine ridge is obvious and well below gums (4mm). No spots or bars are evident on white fur belly or legs.
Older Adult (8-10 years)
Excessive wear and staining of teeth, 20% of canines worn off. Canines ridge well below gum line (4mm).
Incisors worn even or missing. (10 plus years) Most teeth worn to gum line with dark staining.
Differences in Male and Female Genital Spots
Female (1" from anus) Male (4-5" from anus)
Female Lactation Status
First lactation typically occurs at 2 1/2 years. Nipple size and shape relative to lactation status.
(4-5mm) Has never lactated. (8mm wide) Has previously lactated.
